Clean up virtual functions in css/

Source/core/css/CSSImportRule.h

Index: Source/core/css/CSSImportRule.h
diff --git a/Source/core/css/CSSImportRule.h b/Source/core/css/CSSImportRule.h
index f82327644a26ffd938180fab44494b8200727c64..9942d43a4106e680193ec5e67d962411c81b94fb 100644
--- a/Source/core/css/CSSImportRule.h
+++ b/Source/core/css/CSSImportRule.h
@@ -40,7 +40,6 @@ public:
 
     virtual ~CSSImportRule();
 
-    virtual CSSRule::Type type() const override { return IMPORT_RULE; }
     virtual String cssText() const override;
     virtual void reattach(StyleRuleBase*) override;
 
@@ -53,6 +52,8 @@ public:
 private:
     CSSImportRule(StyleRuleImport*, CSSStyleSheet*);
 
+    virtual CSSRule::Type type() const override { return IMPORT_RULE; }
+
     RefPtrWillBeMember<StyleRuleImport> m_importRule;
     mutable RefPtrWillBeMember<MediaList> m_mediaCSSOMWrapper;
     mutable RefPtrWillBeMember<CSSStyleSheet> m_styleSheetCSSOMWrapper;